A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. This can offer a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.

This report describes the design and implementation of the CACC system on two Infiniti FX-45 test vehicles, as well as the data acquisition system that has been installed to measure how drivers use the system, so that the impacts of such a system on highway traffic flow capacity and stability can be estimated. The results of quantitative performance testing of the CACC on a test track are presented, followed by the experimental protocol for on-road testing with human subjects. Finally, the results from the field testing by 16 naïve drivers are presented to show the user acceptance and quantitative measurements of how these drivers used the ACC and CACC systems, and how these systems affected their choice of car following gap.

A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. This can offer a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.

This report describes the design and implementation of the CACC system on two Infiniti FX-45 test vehicles, as well as the data acquisition system that has been installed to measure how drivers use the system, so that the impacts of such a system on highway traffic flow capacity and stability can be estimated. The results of quantitative performance testing of the CACC on a test track are presented, followed by the experimental protocol for on-road testing with human subjects. Finally, the results from the field testing by 16 naïve drivers are presented to show the user acceptance and quantitative measurements of how these drivers used the ACC and CACC systems, and how these systems affected their choice of car following gap.

A Cooperative Adaptive Cruise Control (CACC) system has been developed by adding a wireless vehicle-vehicle communication system and new control logic to an existing commercially available adaptive cruise control (ACC) system. The CACC is intended to enhance the vehicle-following capabilities of ACC so that drivers will be comfortable using it at shorter vehicle-following gaps than ACC. If this is shown to be the case, it offers a significant opportunity to increase traffic flow density and efficiency without compromising safety or expanding roadway infrastructure.

This report describes the design and implementation of the CACC system on two Infiniti FX-45 test vehicles, as well as the data acquisition system that has been installed to measure how drivers use the system, so that the impacts of such a system on highway traffic flow capacity and stability can be estimated. The results of quantitative performance testing of the CACC on a test track are presented, followed by the experimental protocol to be followed for on-road testing with human subjects. Finally, the results from the first pilot test are presented to show how the data are analyzed to reveal the implications of CACC for driving behavior and user acceptance.

The overall IDS research plan was constructed to realize, in slightly more than three years, the requirements, tradeoffs assessment, and technology investigations necessary to define an IDS. Toward the end of the project we will combine our understanding of the problem definition, IDS technologies and our integration experience with a standard Caltrans intersection (with advanced controller) and design a deployable IDS demonstration that can be field-tested.

With the availability of sensing, communication, and computing technologies, IDS systems are promising for the reduction of crashes, fatalities, and injuries on the roadway. Currently, Federal and State governments are partnering with private industries and academia institutions to pursue the deployment of intersection decision support (IDS) and cooperative intersection collision avoidance systems (CICAS), which seek to combine infrastructure-based and vehicle-based functions to provide optimal solutions for roadway users.

This PATH Research Report covers the (Vehicle-Infrastructure Integration) VII California Development and Deployment (Task Order6217) efforts beginning in 2008 and concluding June 30, 2009. This is a successor to the report for TO 5217and reports theapplications-oriented research subsequent to that work.

The report is organized by a synopsis of the background and reasons for the VII California project, then it summarizes some of the antecedent (TO 5217) work: the "Innovative Mobility Showcase" (2005), which established the architecture and, importantly the applications (curve overspeed warning, probe messaging)) and the underlying testbed and enablers (High Accuracy National Differential GPS).